Simplest behavior: null -> exception, like the other params.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/csv/trunk@1578504 13f79535-47bb-0310-9956-ffa450edef68

src/test/java/org/apache/commons/csv/CSVParserTest.java

@@ -719,10 +719,10 @@ public class CSVParserTest {
         CSVParser.parse(null, Charset.defaultCharset(), CSVFormat.DEFAULT);
     }
 
-    @Test()
+    @Test(expected = IllegalArgumentException.class)
     public void testParserUrlNullCharsetFormat() throws Exception {
         final CSVParser parser = CSVParser.parse(new URL("http://commons.apache.org"), null, CSVFormat.DEFAULT);
-        parser.close();        
+        parser.close();
     }
 
     @Test(expected = IllegalArgumentException.class)